Top Voted Answer

You increase them by using them. Using swords or hammers boosts strength, using any guns boosts stature and using magic boosts magical aura. Increasing them gives you a damage multiplier for that type. Also, strength give you more muscles, stature makes you taller and magical aura makes you slightly shinier. The downside is that this also makes the enemies tougher and much more well-grouped. Also makes the leader-type enemies appear (in short, mini-bosses that pop up randomly alongside regular enemies).